When Genetics Collaborate With Trauma: The Impact Of ADHD Genes In Childhood

A large study of over 100,000 people showed that genetics can influence a child's risk of maltreatment, such as abuse or neglect. People with a greater genetic predisposition to ADHD or a lower level of education were more likely to experience this type of trauma. Even when parents have mental health problems, a child's individual genetics still make a difference in risk. This finding could help identify and protect more vulnerable children in the future.

This study investigated whether there is a link between our genes and the likelihood of experiencing maltreatment during childhood, especially in people who also have a psychiatric diagnosis, such as ADHD, autism, or depression.

Researchers analyzed genetic data to better understand whether certain gene combinations increase a child's risk of physical, emotional, sexual abuse, or severe neglect.

To conduct this research, scientists used a large database called iPSYCH, which collects genetic and clinical information from people in Denmark. The study was a case-control design, meaning researchers compared two groups: one with people who had experienced childhood abuse, and another similar group who had not experienced this.

All participants were between 8 and 35 years old, and in total, more than 100,000 people were analyzed. One of the main tools used was the polygenic score (PGS). This score is a measurement created from the combination of many small pieces of DNA, called genetic variants.

Each variant alone has a very small effect, but when added together, they can indicate a person's predisposition to developing certain characteristics, such as risk for ADHD, lower educational attainment, or psychiatric illnesses like depression or schizophrenia.

Using these scores, the researchers divided the participants into groups, called quintiles, representing different levels of genetic risk, from lowest to highest. They then calculated the actual chance (or absolute risk) of a person in each group having experienced childhood maltreatment.

Scientists found that children with a stronger genetic predisposition to ADHD (attention deficit hyperactivity disorder) and those with genes associated with lower educational attainment were at higher risk of experiencing childhood maltreatment.

This means that, even if maltreatment itself is not directly caused by genetics, some people are born with a set of genes that, combined with environmental and family factors, can increase this vulnerability.

The research also showed that children of parents with psychiatric illnesses have more than twice the risk of experiencing maltreatment compared to children of parents without such a diagnosis. However, even within this higher-risk group, researchers were able to identify differences: some children had such a high genetic load that their risk was even higher. This suggests that genetics can be used as a tool to predict who is most at risk.

These findings have great practical importance. By combining genetic information with other known risk factors, such as a family history of mental illness, it would be possible to more accurately identify vulnerable children and thus intervene before harm occurs. This doesn't mean that genetics "determine" someone's fate, but rather that it helps shape the risk scenario.

Furthermore, the analyses showed that the genetic risk of maltreatment is similar for boys and girls, but in practice, the impact is greater for girls: for example, among those with a higher genetic load for ADHD, the risk of maltreatment reached 5.6%, while among boys it was only 2%.

Ultimately, the results reinforce the idea that childhood suffering is caused by a complex interaction between genetic predisposition and family/social environment. Children with a higher genetic risk for ADHD, lower academic performance, or whose parents have mental illness are those most in need of protection.

The study does not seek to place blame on genes or parents, but rather to provide tools to improve prevention and care, more accurately identifying those who need help.

READ MORE:

Genetic Architecture and Risk of Childhood Maltreatment Across 5 Psychiatric Diagnoses

Trine Tollerup Nielsen, Paraskevi Bali, Jakob Grove, Christina Mohr-Jensen, Thomas Werge, Søren Dalsgaard, Anders D. Børglum, Edmund Sonuga-Barke, Helen Minnis, Ditte Demontis, and the Autism Spectrum Working Group of the Psychiatric Genomics Consortium

JAMA Psychiatry, May 9, 2025; 82; (8) : 790-800. 

doi:10.1001/jamapsychiatry.2025.0828

Abstract: 

Childhood maltreatment (CM) is associated with psychiatric disorders. The underlying mechanisms are complex and involve genetics. To investigate the polygenic architecture of CM-exposed individuals across psychiatric conditions and if genetics modulates absolute CM risk in the presence of high-impact risk factors such as parental psychiatric diagnoses. The population-based case-cohort iPSYCH was used to analyze 13 polygenic scores (PGS) in CM-exposed individuals across 5 psychiatric International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) diagnoses benchmarked against controls. Individuals were stratified into PGS quantiles, and absolute CM risk was calculated using Cox regression. Sex-specific analyses were also performed. Data were analyzed from June 2022 to December 2024. PGS of phenotypes of psychiatric disorders, CM, educational attainment, and substance use. PGSs were generated using summary statistics from genome-wide association studies of phenotypes representing psychiatric disorders, CM, educational attainment, and substance use and tested for their association with CM across psychiatric disorders. This study included 102 856 individuals (mean [SD] age, 22.6 [7.1] years; 54 918 male [53.4%]) 8 to 35 years old. A total of 2179 CM-exposed individuals were analyzed across individuals with attention-deficit/hyperactivity disorder (ADHD; n = 22 674), autism (n = 18 941), schizophrenia (n = 6103), bipolar disorder (n = 3061), depression (n = 28 896), and controls (n = 34 689). PGSs for ADHD and educational attainment were associated with CM across all psychiatric diagnoses. The absolute CM risk was increased in the highest PGS groups, eg, for ADHD, the absolute CM risk was 5.6% in the highest ADHD-PGS quartile whereas it was only 3.3% in the lowest ADHD-PGS quartile (hazard rate ratio quantile 4 vs quantile 1 = 1.81; 95% CI, 1.47-2.22). CM risk was more than twice as high for children with parents with a psychiatric diagnosis (5.7%) than for children with parents without a psychiatric diagnosis (2.5%), but even in the presence of this risk factor, individuals could still be stratified into risk groups based on their genetics. No genetic differences between CM-exposed males and females were observed, but there were striking sex differences in absolute CM risk, which reached 5.6% for females in the highest ADHD-PGS quartile and 2.0% for males. Results of this case-control study suggest that individuals with high ADHD-PRS and/or low educational attainment–PRS had an associated elevated risk of CM. Extra attention should be given to individuals at high risk for CM across all 5 psychiatric diagnoses, ie, females with a high ADHD-PGS and/or a parent diagnosed with a psychiatric disorder.